Coverings for buildings must comply with essential requirements for a simple assembly that is lightweight, impermeable and reliable, with the goal of effectively protecting the surface of the covering, without requiring a supporting structure that is excessively strong.
There are conventional coverings that are formed by placing covering elements on a flat surface, such as tiles, slate or waterproof membrane, and these types of coverings are widely used. However, due to the types of materials these coverings are made up of, there are several inconveniences to them, such as the heavy weight, the need to have a support surface for the assembly and a very tedious installation.
There are also coverings made up of lightweight, plastic plates, or of other similar materials, the plates fastened by elements that require through holes on the plates. These types of coverings are light, only requiring support points to be fastened, and the assembly and installation are done quickly, since each plate covers a large area. However, due to the type fastening elements used, the installation is complicated and the holes for fastening the plates increase the risk of leakage through said holes.
There are alternative solutions for coverings by using metal sheets with bends by which the sheets are joined together and fastened to supports, such that the interconnected bends of the sheets make is so that each sheet overlaps the next one, thereby creating an impermeable connection between the sheets. For example, some solutions of this type are those described in the following patents: ES 2 125 376 T3, ES 2 217 061 T3, ES 2 229 579 T3, ES 2 329 844 T3 and ES 2 322 667 T3. However, all of these solutions are based on assemblies of metal sheets that are complex and expensive to manufacture and, furthermore, in some cases they do not guarantee a secure connection with proper sealing.